Facial Neuromuscular Retraining for Facial Paralysis

Facial weakness or paralysis can occur after surgery to remove a vestibular schwannoma (acoustic neuroma). Fortunately, with improved surgical techniques, improved diagnostic capabilities and facial nerve monitoring, it is much less common.*1 Rinaldi et al in their study in 2012 showed that the size of the tumour was one of the most important factors in determining if facial nerve function would be affected by microsurgery. *2 If the tumour is large, entangled with the facial nerve or compressing the nerve over a prolonged period, the nerve may be fragile and a facial palsy may result. Dr. B. Azizzadeh of the Facial Paralysis Institute, https://www.facialparalysisinstitute.com/, estimates the risk of developing facial paralysis from an acoustic neuroma is between 4 to 15%.

Our faces are used for communication, eating, drinking, whistling and expression of emotion. When the face is affected it cannot be hidden below a cast or clothing, it is there for all to see. Many say that people ask them if they’ve just been to the dentist or if they’ve had a stroke. Altered facial movements can have a huge emotional impact, and in some cases, more than the decrease in motor function.

Facial Neuromuscular Retraining (FNR) has been gaining approval and has been shown to be effective at improving facial function.*3 For years it was felt that brain development was complete by the end of adolescence and any injury that occurred afterwards was permanent. Studies have shown that this is not the case as other parts of the brain can take over lost function. This concept is called neuroplasticity and along with feedback, is the cornerstone of Facial Neuromuscular Retraining.

When should you see a facial therapist?

There are many people who think that you should wait to see a facial therapist until there is visible return of movement. However, we have received feedback from many patients that they wished they had seen us in the beginning. In the stage before movement recovery there are a number of important issues. First is the lack of eye closure. The chance of corneal abrasions, dehydration or even ulcerations is very high since the eye cannot close or blink. We like to work in tandem with an ophthalmologist and review eye care, taping and lubricants for the eye. We also like to go over what to do and what not to do with people while they are waiting for recovery. “Dr. Google” is a popular place to find information for people left to their own devices. The internet is full of prescriptions for doing forceful facial exercises before there is return of movement. This does more harm than good as it causes the face to pull more to the unaffected side and does nothing for the affected side. In addition, electrical stimulation is often advocated in this early stage. However, research suggests that this may actually affect the facial nerve’s ability to regrow. It also can cause mass action where many muscles contract at the same time. Massage and moist heat are recommended to keep the circulation to the facial muscles while there is no movement. Most of all, education is key at this stage. If there is recovery of movement within the first few months, no further therapy would be needed.

As the facial nerve starts to heal, changes are first seen in how the face is at rest. As nerve recovery continues, muscle twitches and small movements begin to appear. This is an ideal time to go back to see the facial therapist for guidance on how to practice these movements. Facial expressions are, on the whole, quite soft and low effort. It is important that movements be practiced in this way and not like you would ordinarily strengthen skeletal muscles. No weight lifting here! Additionally, you and the facial therapist will be on the lookout for synkinesis. These are abnormally connected movements e.g. eye narrowing when you move your mouth. Careful training to separate these movements will need to be practiced. Your therapist will recommend specific movement strategies for you to do at home. Norman Doidge in his book The Brain that Changes Itself *4, writes that “neurons that fire together, are wired together”. This is good when you are trying to learn a new sport or skill but can also apply to synkinesis. Your facial therapist will help you to “unwire” undesirable movements and “wire” together desirable ones.

Facial Neuromuscular Retraining is done on a daily basis at home. Follow-up with the facial therapist ideally is monthly at the beginning. As the home exercise program is well established, visits with the facial therapist are less often. There is little way to predict how well someone will do as there are so many factors that affect outcome: motivation, amount of facial nerve damage, amount of time after surgery, and compliance with the program. It is hard to find printed “exercises” for this type of treatment as each patient is assessed and treated individually. Their program is good only for them and as long as they practice, they will make changes. Most of our patients have said that Facial Neuromuscular Retraining allowed them to be in control of their faces instead of the other way around.

References

1. Silverstein, H, Rosenberg, SL, Flanzer, J, Seidman, MD; Intraoperative Facial Nerve Monitoring in Acoustic Neuroma Surgery: Am. J. Otol. 1993 Nov;14(6):524-532,
2. Rinaldi, V, Casale, M (...) and Salvinelli, F; Facial Nerve Outcome after Vestibular Schwannoma Surgery: Our Experience: J. Of Neurological Surgery. Part B, Skull Base: 2012 Feb, 73, 73(1), 21-27.
3. Pereira, LM, Obara, K, Dias, JM, Menacho, MD, Lavado, EL, Cardosa, JR; Facial Exercises Therapy for Facial Palsy: Systematic Review and Meta-Analysis. Clinical Rehabilitation 2011 Mar,, 25(7), 649-658.
4. Doidge, Norman, The Brain That Changes Itself: Viking Penguin, 2007

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